Liam knows the key to making creamy risotto, a rice dish, is to add the liquid to the rice gradually. He adds 5 ladles of chicken broth to his rice before adding seasoning, and he continues to add 2 ladles of broth each minute afterwards. Write an equation that shows the relationship between the number of minutes since Liam added the seasoning, x, and the total number of ladles of broth he has added, y.